Technical Field
The present invention relates to a system for determining thermal properties of wall assemblies under dynamic weather conditions. The system comprises a house-like structure with a suite of measurement devices to measure temperatures, heat fluxes, and weather conditions.
Description of the Related Art
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.
Energy concerns are critical to the modern society. Therefore, the proper use of thermally efficient wall assemblies can reduce the energy consumption in buildings. To achieve this goal, the thermal transmittance and thermal resistance of wall assemblies must be known. These thermal properties are usually determined with equipment, such as guarded hot plates, and guarded hot boxes, and by methods (PARONEN, M, Canada Patent Application 2870379; AHMAD, A., U.S. patent application Ser. No. 13/681,327—each incorporated herein by reference in its entirety) which test wall assemblies under controlled conditions. Hence, the results are valid only for specific test conditions, and can be a poor predictor of performance if the conditions of use vary from those of the test.
The actual thermal performance of a material depends on system effects, airflow, and its orientation to the sun. For example, the buildings could be constructed in a way that does not replicate the method used during the testing of the material. Airflow through a structure, driven by wind, stack effect, and mechanical equipment, can also transport significant amounts of heat. Heat flow varies over time as the outdoor air temperature varies (on an hourly, daily, and seasonal basis) and as the sun heats the exterior surfaces. These dynamic variations are important for the accurate determination of thermal performance of a material.
In view of the forgoing, the objective of the present invention is to provide a system and a method for determining thermal transmittance and thermal resistance.